Electromagnetic regulator



Sept; 23, 1947. w. G.-NE1LD 2,427,806

ELECTROMAGNET I C REGULATOR Filed March 20, 1945 Jnveni'Ol.

W1 paw/u.

ATTGRNE Y Patented Sept. 23, 1947 ELECTROMAGNETIC REGULATOR William G.-Neild, Warren Point, N. J.;-aseignor to Bendix Aviation Corporation, Teterboro, N. 1., a corporation of Delaware Application March 20, 1945, Serial No. 583,812 Claims. (01. 201-51) have come into widespread use for such pur-' poses as controlling the voltage of the output of generators and also in the governing of current.

All of these carbon pile regulators operate on the principle of varying the pressure applied to the carbon pile; the range of effective pressure on the pile being the regulating range of the regulator.

There has now come into fairly widespread use a regulator which is characterized as including the usual carbon pile, one end of which is relatively fixed. Operatively associated with the other end to apply pressure on the pile, is an armature and this armature is carried by a spring of the leaf type having a plurality of spring fingers which engage at the extremities thereof. an inclined abutment formed on the electromagnet.

The force of the electromagnet is rendered effective on the armature. and the spring above referred to, tends to urge the armature towards the pile, while the magnetic force tends to withdraw the armature from the pile and to force the spring fingers into abutting relation along the inclined surface of the abutment provided on the electromagnet so as to approximately vary the force exerted by the spring inversely as the square of the distance between the armature and magnet so as to effect basic correspondence.

With carbon pile regulators of this type considerable mechanical difliculty has been experienced in obtaining desired regulating eflects due to the difiiculties incident to calibrating the several spring fingers to the inclined abutment, so as to give the effect desired. Moreover, the latter spring has a'characteristic which outside its normal lhnited working range and with lower forces is quite diiierent from that within its limited working range. Thus upon wear of the carbon pile-which inevitably results through use,

this latter characteristic oftenresults in high voltage and consequent failure of control and damage to the electrical system.

An object of the present invention, therefore, is to simplify and improve the aforenoted spring construction. 1

Another object of the invention is to provide a leaf spring of normal flat construction and adapted to be clamped between a novel armature and supporting structure so that upon moveformed of a suitable ferromagnetic material.

ment of the armature towards the electromagnet, the leaf spring will fall along an incline and at an angle such as to progressively increase the resistance of the spring to displacement of the armature, and thereby provide the desired regulative effect.

Another object of the invention is to provide an armature spring arrangement of the type described of high eflic'iency and of such simplicity in construction as to be readily adaptable for manufacture and installation at low cost.

Another object of the invention is to provide a novel arrangement whereby an over-regulated or excessive voltage or current condition may not result upon wear of the carbon pile element.

These and other objects and features of the invention are pointed out in the following description in terms of the embodiment thereof which is shown in the accompanying drawings. It is to be understood, however, that the drawings are for the purpose of illustration only, and are not designed as a definition of the limits of the ,invention, reference being had to the appended claims for this purpose.

Figure .1 is a fragmentary view of a regulator embodying one form of the invention.

Figure 2 is a fragmentary sectional view of a modified form of the invention.

Referring to the drawing of Figure 1, there is provided a bottom plate I on which is mounted a casing I. The bottom plate and easing 2 are A core 5 of similar material projects from the bottom plate i into an electromagnetic winding 'I wound about the core 0 and positioned within the casing I.

Positioned on the casing 2 is an annular member II which is fastened to the bottom plate i' by suitable screws i2, one of which is shown in the drawing.

Ahousing ilofatypesuchasshowninmycopending application Serial No. 570,002, filed December 27, 1944, i fastened to the annular member it by screws ll.

'mature plate 30. The contactor member II is positioned in a cup shaped securing member 40 mounted on the armature plate it.

The armature plate 30, a shown in Figure 1,

is positioned at one side of a leaf spring 45. At the opposite side of the leaf spring 45 is positioned a second armature plate 48 and the leaf spring 45 is clamped between the armature plates 36 and 48.

As shown in Figure 1, the leaf spring 45 is clamped at one end between a bar 48 and the top surface of the annular ring I by bolts 41 so as to form. a flexible hinge mounting at one side of the armature.

The leaf spring 45 is dished at the other side of the armature so as to form an angle A" with the horizontal top surface of armature plate 55 and an angle 13" at its other end with the horizontal surface of the annular member I. The leaf spring 45 is held in the latter position through clamping plate 50 fastened to the annular member H! by bolts 5|. The armature plate 48, annular member l0 and respective clamping plates 36 and 50 have suitable mating surfaces arranged to clamp the leaf spring 45 in the lat ter position.

As shown in Figure 1, as the armature moves towards the electromagnet the leaf spring 45 falls along a line represented by an extension of the incline at which the leaf spring 45 is clamped between the plate 50 and annular member Ill. The portion of the spring 45 which falls along this line is of a continuously increasing length as the armature 46 moves towards the electromagnet. Thus the length of the spring 45 subject to further bending as the armature 45 moves further towards the electromagnet continuously decreases. The leaf spring 45, thus shortens and becomes stiffer as the length of the air gap decreases. Thus by appropriate selection of the spring 45 and the angles A" and B at which the spring 45 is clamped the resistance of the leaf spring 45 is readily made to vary in a non-linear relation or approximately inversely as the square of the distance between the point of application of the magnet pull to the spring and some fixed datum point so that basic correspondence with the varying magnet pull results.

Through the latter arrangement, it will be seen that the leaf spring 45 is so clamped that the same may not slip and therefore the vertical force component of the spring is obtained by breaking the force components acting along the spring 45, into two components, that is horizontal and vertical force components.

Since the leaf spring 45 i clamped in position so as not to slip, the horizontal force components of the spring in turn set up vertical forces opposing movement of the armature towards the core 5 of the electromagnet I, which forces vary substantially inversely as the square of the distance of the armature 45 from the core 5 so as to eifect basic correspondence with varying magnet pull results.

Moreover, by clamping the leaf spring 45 in the manner indicated, it will be seen that the spring force exerted progressively decreases as the armature 45 moves away from the core 5 and such progressive decrease in spring force is maintained to the limit of movement of the armature by clamping the end of the spring 45 to the annular member II by the plate 50.

Thus it will be seen that as the leaf spring 45 approaches its limit of movement it will not overbalance the force of the electromagnet at a given regulated voltage or regulated current. Thus by clamping the leaf spring 45 in the manner indicated the spring 45 is prevented from overbalancing the magnetic force at a given regulated current or voltage so that over regulated or excessive voltage or current may not result even upon the pile becoming so worn as to cause failure of the regulator. This feature greatly lengthens the life of the regulator.

In Figure 2 a modified form of the invention is shown in which'both end of the leaf spring 45 are dished and clamped to the annular member IDA by plates 50A and 503 secured to the annu lar member IDA by bolts HA and MB. An armature 48A, annular member NA and respective clamping plates 35A and HA and MB have suitable mating surfaces arranged to clamp the leaf spring 45 in the position shown so as to form the angle A with the horizontal surface of armature plate 35A and its outer end the angle 44B."

In the latter form of the invention, as in Figure 1 the leaf spring 45 is progressively positioned into alignment with the portion clamped at the annular supporting member It as the armature 48A moves towards the core 5 so as to progressively decrease the length of the leaf spring 45 subject to further bending as the armature 45A moves towards the core 5. The same is arranged so that basic correspondence with varying magnet pull results.

The angles A and 3" heretofore noted may for example, have a value of 9 degrees and 8 degrees respectively. This value, however, may be varied to meet the specific essentially nonlinear force characteristics of the electromagnet involved so as to effect basic correspondence with the varying magnet pull results.

Although only two embodiments of the invention have been illustrated and described, various changes in the form and relative arrangements of the parts, which will now appear to those skilled in the art, may be made without departing from the scope of the invention. Reference is, therefore, to be had to the appended claims for a definition of the limits of the invention.

What is claimed is:

1. In an electric regulator of the type including a variable resistance element, an electromagnet having an essentially non-linear force characteristic and an armature operated by said electromagnet and operably connected to said variable resistance element; the improvement comprising a leaf spring clamped to said armature and providing the sole spring force applied to said armature, a supporting member, one end of said leaf spring clamped to said supporting member so as to form a flexible hinge for said armature, a fastening member having an inclined surface cooperating with a like surface on said supporting member for clamping the opposite end of said leaf spring to said supporting member and at a first acute angle to the armature, and said armature including a pair of fastening members having cooperating inclined surfaces arranged to clamp said leaf spring therebetween at a second acute angle to the armature so that upon movement of said armature toward said electromagnet said leaf spring will be progressively moved into alignment with said clamped portion at said first acute angle and in such a manner as to progressively increase the resistance of said leaf spring to movement of said armature in a nonlinear relation corresponding to said electromagnet force.

2. In an electric regulator of the type includinga variable resistance element, an electromagnet having an essentially non-linear force characteristic. and an armature operated by said electromagnet and operably connected to said variable resistance element; the improvement comprising a leaf spring clamped to said armature, said armature including a pair of members having inclined surfaces between which said leaf spring is clamped, a supporting member, members for clamping the opposite ends of said leaf spring to said supporting member and at a predetermined angle so as to flexibly support said armature in relation to said electromagnet, said leaf spring so arranged in relation to said clamping members as to progressively decrease the force applied to said armature in a non-linear relation. corresponding to said electromagnet force as the air gap between said armature and electromagnet is increased, and said clamping members fastening the opposite ends of said spring member so as to limit and prevent the force exerted by said leaf spring from exceeding the force exerted by said electromagnet upon energization of said electromagnet at a predetermined value so as to prevent over regulation upon wear of said variable resistance element.

3. In an electrical regulator of the type including a variable resistance carbon pile element, an electromagnet having an essentially nonlinear force characteristic, and an armature operated by said electromagnet and operably connected to said variable resistance carbon pile element; the improvement comprising a leaf spring clamped between said armature, said armature including members for fastening portions of said leaf spring therebetween and at predetermined angular relations so as to project from said armature at acute angles thereto, an annular supporting member affixed to said electromagnet, and having inclined surfaces, clamping members having inclined surfaces cooperating with the inclined surfaces of said support and provided at opposite ends of said leaf spring to clamp said leaf spring to said supporting member and at acute angles to said armature so as to form a depression in said leaf spring at opposite sides of said armature, said leaf spring so arranged as to progressively decrease the force applied to said armature in a non-linear relation corresponding to said electromagnet force as the air gap between said armature and electromagnet is increased so as to balance the force exerted by said electromagnet upon energization thereof at a predetermined value, and said clamping members securing the opposite ends of said leaf spring so as to limit the movement of the armature in a resistance decreasing direction to prevent over regulation of said variable resistance carbon pile element upon wear of said carbon pile.

4. In an electric regulator of the type including a variable resistance element, an electromagnet having an essentially non-linear force 60 2.33 .52

characteristic, and an armature operated by said eleetromganet and operably connected to said variable resistance element; the improvement comprising a spring member, said spring member clamped to said armature and providing the sole spring force acting on said armature, a supporting member, members for clamping the free ends of said spring member to said supporting member and in a predetermined angular relation so as to flexibly support said armature in relation to said electromagnet and effect a continuous decrease in the force applied to said armature by said spring member as the air gap between said armature and electromagnet is increased and in a non-linear relation corresponding to said electromagnet force, and said clamping members so arranged as to limit the movement of the armature under force of said spring member and prevent the force exerted by said spring member from exceeding the force exerted by said electromagnet upon energization of said electromagnet at a predetermined value so as to prevent over regulation upon wear of said variable resistance element.

5. In an electric regulator of the type including a variable resistance element, an electromagnet having an essentially non-linear force characteristic, and an armature assembly; the improvement ,comprising resilient means supporting said armature assembly and opposing the pull of said electromagnet including a spring member having one portion secured to said armature at a predetermined acute angular relation, a supporting member, said spring member extending laterally to said supporting member, means for firmly clamping the outer portion of said spring member to the supporting member and at a second predetermined acute angular relation so as to provide in said spring member an intermediate curved portion movable with said armature assembly under the action of said electromagnet and in a direction tending to cause said spring member to straighten along a line formed by an extension of the line of said second angle and developing a tension force continuously increasing in excess of a linear relation as said armature approaches said electromagnet.

WILLIAM G. NEILD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,268,718 Newton Jan. 6, 1942 22,332,140 Finnegan Oct. 19, 1943 Allen Dec. 14, 1943 

